Two decades ago, most hearing aids dispensed were of the Behind-the-Ear (BTE) type, i.e. a hearing device situated behind the ear with an acoustic tube connecting the device to an earmold placed within the canal. Subsequently, smaller In-the-Ear (ITE) models were introduced. The increasing miniaturization of electronic circuitry and improvements in battery technology have made the development of smaller In-the-Canal (ITC) and Completely-In-the-Canal (CIC) hearing devices possible. The marked reduction in size of these canal devices (both ITC and CIC), coupled with their deep placement within the ear canal, provides an obvious cosmetic advantage to wearers of hearing devices. The reduced residual volume in the ear canal and the proximity of the hearing device receiver (speaker) to the tympanic membrane resulting from deep canal placement of a hearing device provide other advantages, such as improved overall sound fidelity, improved high frequency response, reduced distortion, reduced occlusion effect, improved sound localization, reduced wind noise, and improved use with telephones.